Boat hoist



R. B. SMITH BOAT HOIST Nov. 9, 1965 Filed Dec. 30, 1963 2 Sheets-Sheet lINVENTOR. RUSSELL B. SM/TH BY (R CLCPM R. B. SMITH Nov. 9; 1965 BOATHOIST 2 Sheets-Sheet 2 Filed Dec. 50. 1963 INVENTOR. RUSSELL B. SM/THATTORNEY llll llllll United States Patent 3,216,704 BOAT HOIST RussellB. Smith, E. Spaulding Bldg., Battle Creek, Mich. Filed Dec. 30, 1963,Ser. No. 334,126 11 Claims. (Cl. 254-128) The present invention relatesbroadly to lifting equipment, and more specifically to a boat rasing andlowering mechanism adapted to be placed in the water alongside a dock towhich the boat would be normally moored.

It is the standard practice with small boats to either drag them out ofthe water onto shore or onto a dock, or else anchor them out inmoderately deepv water or tie them to the side of a dock for storagebetween times of use. These various procedures are all subject todisadvantages, such as scraping paint from the boat hull, along with thehard work involved in pulling the boat out of the water, getting to andfrom a boat anchored out from shore and away from a dock, and lastly,where a boat is anchored to the side of a dock there is the matter ofthe boat chafing and banging against the side of the dock under the waveaction caused by passing boats, as well as bad weather.

In recognition of the above ditficulties several devices have beenproposed for use in lifting the boat out of the water alongside of adock when the boat is to be left unattended for any period of time. Thispreviously proposed apparatus has had many drawbacks for the ordinarysmall boat owner, such as being too complex and expensive, unreliable,too difficult to use, nonadjustable, or the like. It was a recognitionof these shortcomings in the previously attempted solution of theproblem of how to get a small boat out of the water alongside a clockwhich led to the conception and development of the present invention.

Accordingly, among the objects of the present invention is the provisionof a highly simplified and low-cost boat hoist which can be set in thewater alongside a boat dock, with all but the hoist actuating portionbeing under water when not in use.

Another object is to provide'a hinged mechanism adapted to engage thebottom of the boat, fore and aft, for lifting purposes and with thelifting power of the mechanism increasing as the boat is lifted.

Another object is to provide a boat hoist which not only has a winch orthe like for use in lifting and lowering the boat but also supplementallifting aids such as a power increasing pulley and cable assembly and/ora semi-toggle action link arrangement.

A further object is to provide a boat hoist which has frame levelingsupport members so that the boat hull engaging members willsubstantially simultaneously engage same fore and aft when the boat isto be raised,

A further object is to provide a boat hoist wherein a major portion ofsame can be made from the standard parts found on the open market, andwhich is of moderately low cost, easily operated, and very stable inuse.

Still further objects and advantages of the invention will appear as thedescription proceeds.

To the accomplishment of the foregoing and related ends, the invention,then, consists of the hoist means hereinafter fully described andparticularly pointed out in the claims, the annexed drawings and thefollowing description setting forth in detail certain means for carryingout the invention, such disclosed means illustrating, however, butseveral of various ways in whic the principle of the invention may beused.

In the annexed drawings:

FIGURE 1 shows a perspective view of the boat hoist ice of the presentinvention with the boat hull contacting members in partially elevatedposition.

FIGURE 2 is a side elevation of the boat hoist hull contacting membersin elevated position, while their lowered position is shown in dashedlines.

FIGURE 3 is a cross sectional view of the boat hoist as taken along lineIII-III of FIGURE 2, look ing in the direction of the arrows.

FIGURE 4 is a sectional view as taken along line IV-IV of FIGURE 2,looking in the direction of the arrows.

FIGURE 5 is a sectional view as taken along line VV of FIGURE 3, lookingin the direction of the arrows.

FIGURE 6 is a fragmentary end view of the rear supporting assembly astaken along line VIVI of FIGURE 2, looking in the direction of thearrows.

FIGURE 7 is a fragmentary central top section view as taken along lineVII-VII of FIGURE 2, looking in the direction of the arrows.

FIGURE 8 is a fragmentary sectional view as taken along line VIIIVIII ofFIGURE 7, looking in the direction of the arrows.

FIGURE 9 is a fragmentary sectional view of a modified form of the winchactuating mechanism wherein an electric motor is used to supply the boathoist operating power.

Referring to FIGURE 1 of the drawings, it will be noted that the boathoist assembly 10 has bottom side rails 11 and 12 with a front crossrail 13 and a rear cross rail 14 joining said bottom side railstogether. Said front cross rail 13 is threadedly or otherwise connectedat its ends to elbow fittings 15 and 16 with the opposite end of each ofsaid elbow fittings, respectively, threadedly or otherwise joined to thecorresponding ends of said bottom side rails 11 and 12. Welded orotherwise fastened to said elbow fittings 15 and 16 are tubular members17 and 18 which extend substantially perpendicular to the plane of saidelbow fittings. The rear cross rail 14 is joined at its ends to siderails 11 and 12 by means of T-fittings 19 and 20 which are preferablyslid onto and then anchored in place to said side rails in any suitablemanner such as by welding or brazing. At the outer end of bottom siderails 11 and 12, adjacent rear cross rail 14, they are provided withT-fittings 21 and 22 mounted in planes perpendicular, respectively, tothat of T-fittings 19 and 20. Said T-fittings 21 and 22 may be anchoredin place on the ends of bottom side rails 11 and 12 in any conventionalmanner, such as by threading, welding or brazing.

In order to provide good bottom support for the rear cross rail end ofthe boat hoist assembly 10, endwise adjustable tubular members 23 and 24are mounted on and pass through T-fittings 21 and 22 for endwiseadjustment and anchoring by means of setscrews 25 and 26 as shown inFIGURE 1. Adjacent the lower end of said tubular members 23 and 24, theyare provided with supporting plates 27 and 28 perpendicular thereto andanchored to same in any conventional manner, such as by welding orbrazing. The lower end of said tubular members 23 and 24 preferablyextends below supporting plates 27 and 28, FIGURE 2, so as to resistshifting of the boat hoist assembly 10. The tubular members 17 and 18 atthe ends of front cross rail 13 are also preferably provided with anextended through supporting plates 29 and 30, FIGURE 3, and may beanchored to same in any conventional manner, such as by welding orbrazing.

Connecting the central portion of front cross rail 13 to the centralportion of rear cross rail 14, by means of T-fittings 31 and 32conventionally anchored thereto,

is a tubular connecting member 33. Closely fitting on connecting member33 is a stilfening and reinforcing tubular member 34, the forward end ofwhich is preferably positioned by a stop pin 35, FIGURE 7, while therearward end may be stopped by a threaded rod 36 with adjusting nuts 37and 38, FIGURE 2. The lower end of threaded rod 36 is prefrably providedwith a supporting plate 39 to support the central portion of connectingmember 33 under conditions of use of the boat hoist assembly 10, as willbe hereinafter described.

Mounted on rear cross rail 14 is rear supporting assembly 40 which has atop rail 41 with elbow mounting rnembers 42 and 43 on its ends, FIGURES1 and 6. Supporting arms 44 and 45 threadedly engage said elbow mountingmembers 42 and 43 and extend down to T-fittings 46 and 47, FIGURE 1,rotatably mounted on rear cross rail 14. These T-fittings 46 and 47 areheld in suitable position, as shown in FIGURE 1, by means of adjustableposition stop collars 48, preferably of the type shown in FIGURE 6.Supporting arms 44 and 45 are preferably made adjustable in length tomeet varying requirements of the boat hoist, for instance, by cuttingthem in two, FIGURE 4, and fitting a sleeve 49 over the cut ends andproviding this sleeve 49 with setscrews 50 adjacent each end of same foranchoring the cut ends at predetermined spacing from each other.

Mounted on top rail 41, FIGURES 1 and 6, are a pair of boat keelsupporting members 51 and 52 which are preferably provided on the boatkeel contacting face of same with suitable fiber or rubber padding 53and 54. The rear end of these keel supporting members are preferablymade slightly heavier than the front end of same so that they will tiltslightly as shown in FIGURE 1 to facilitate the passage of a boat 55thereon. These keel supporting members 51 and 52 are preferably held inpredetermined position on top rail 41 by means of stop collars 56,FIGURE 6, having setscrews 57.

Mounted on front cross rail 13, FIGURES 1 and 3, is a front supportingassembly 58 which has a top rail 61 with elbow mounting members 59 and60 threadedly fastened on its ends. Supporting arms 62 and 63 threadedlyengage said elbow mounting members 59 and 60 and extend down toT-fittings 64 and 65 rotatably mounted on front cross rail 13. TheseT-fittings64 and 65 may be held in suitable position, as shown in FIGURE3, by means of conventional adjustable position stop collars 66. Mountedon top rail 61 are a pair of boat prow supporting members 67 and 68which are preferably provided on the prow contacting face of same withsuitable fiber or rubber padding 69 and 70. The rear end of these prowsupporting members are also preferably made slightly heavier than thefront end of same so that they will tilt slightly as shown in FIGURE 1to facilitate the passage of the boat 55 thereon, FIGURE 2. These prowsupporting members 67 and 68 are preferably held in predeterminedposition on top rail 61 by means of stop collars 71, FIGURE 3, havingsetscrews 72.

Freely mounted for rotation on top rail 61, between prow supportingmembers 67 and 68, is a T-fitting 73 with the side connecting portion ofsame threadedly connected to an operating link 74, the lower end ofwhich has pivotally mounted thereon as by means of a bolt 75, FIGURE 8,a slide fitting 76 which slidably engages tubular reinforcing member 34carried by connecting member 33 with said slide fitting 76 being freelyslidable on said reinforcing member 34.

In order that front supporting assembly 58 will pivotally movesubstantially in unison with rear supporting assembly 40, the two areconnected together, for instance, by cable means 77. This cable means ispreferably connected in a generally V-pattern as shown in FIGURE 1, withthe wide end of the V being joined to the rear supporting assembly 40near the inside faces of supporting members 51 and 52. If desired, thetop rail 41 of rear supporting assembly 40 may be suitably perforated sothat the two ends of cable means 77 can be threaded therethrough andthen anchored, for instance, by tying them together with a clamp or knot78. The front end of cable means 77, FIGURE 1, instead of beingconnected direct to top rail 61 of front supporting assembly 58, ispreferably connected to operating link 74 near to T-fitting 73 on theupper end of same and conventionally anchored against shifting on sameto stabilize top rail 41 of rear supporting assembly 40 from shiftingout of substantial parallelism with rear cross rail 14. Connecting cablemeans 77 in this manner to operating link 74 has the further advantageof putting a rearward pulling force on operating link 74 so that slidefitting 76 is normally urged to slide rearward on tubular reinforcingmember 34 to thus facilitate the simultaneous pivotal movements of frontsupporting assembly 58 and rear supporting assembly 40.

The pivotal raising and lowering of front supporting assembly 58 andrear supporting assembly 40 in unison to raise and lower boat 55 may bereadily accomplished, for instance, as shown in FIGURE 1. Here tubularmember 18 has fitted into the top of same a tubular upright 79 carrying,adjacent its upper end, a winch 80 of conventional releasable latch typehaving a drum 98 rotatable by an operating crank 81. To stabilizeupright 79 there is provided a brace member 82 connected at its upperend to tubular upright 79 by means of a Y-fitting 83 and at its lowerend to bottom side rail 12 by means of a second Y-fitting 84. The upperend of tubular upright 79 may be closed, if desired, by means of a cap85. An operating cable 86 is fastened to drum 98 of winch 80 so thatsame may be wound and unwound therefrom as boat 55 is being eitherraised or lowered as will now be described.

Operating cable 86 extends down from winch 80 to a pulley 87conventionally fastened to tubular upright 79, for instance, by means ofan eye-bolt 88, FIGURE 1, near the lower end of upright 79. This cable86 then extends inward to a second pulley 89 fastened in similar mannerto connecting member 33 adjacent T-fitting 31, from whence the cable 86passes through a third pulley 90 fastened by means of an eye-bolt 91,FIGURE 8, to bolt which mounts slide fitting 76 on the lower end ofoperating link 74. After passing through third pulley 90, FIGURE 1, theend of cable 86 is fastened to another eye-bolt 92 connected toconnecting member 33 adjacent T-fitting 31. Since the run of cable 86from the second pulley 89 to the third pulley 90 is substantiallyparallel to the run of cable 86 from the third pulley 90 to eye-bolt 92,the movement of cable 86 as it is being wound on drum 98 of winch istwice as fast as the movement of slide fitting 76 on reinforcing member34. This alone provides a mechanical advantage of two which added to themechanical advantage of winch 80 and the toggle action obtained throughmoving the lower end of operating link 74 toward T-fitting 31 is suchthat a moderate operating force on winch 80 will lift a moderately heavysmall boat out of the water, as shown in FIG- URE 2.

While a hand-operated winch utilizing an operating handle 81 has beendescribed above, the invention is not limited to that particularconstruction since, as shown in FIGURE 9, the winch 80a may be driven bya suitable reversible and geared down electric motor 93 mounted on ashelf member 94 conventionally supported on tubular upright 79 by meansof bolts 95. In preferred form the Y-fitting 83 is in the form of adouble Y so that a second brace member 96, FIGURE 9, may be used andconnected by a Y-fitting 97 to front cross rail 13.

Referring now to FIGURE 2, when the front and rear supporting assemblies58 and 40, respectively, are in the lowered dashed-line position, theyare ready to have a boat 55 floated thereonto. Then, by operating winch80 to wind operating cable 86 thereon, this cable will move slidefitting 76 to the left along reinforcing member 34, and through themovement of slide fitting 76 and its connection to operating link 74,the front and rear supporting assemblies are moved to the solid lineposition, with the boat 55 elevated above normal water level as shown.

To install the boat hoist, it is preliminarily assembled as shown inFIGURE 1 and then carried out and lowered into suitable depth wateralongside the conventional small boat dock, with the winch carryingportion of same preferably at the shore end of the boat hoist andadjacent the side of the dock with side rail 12 likewise extending alongthe dock and close to same. With the boat hoist thus in the water, thetubular members 23 and 24, respectively, having supporting plates 27 and28 on the lower ends of same,.are adjusted through T-fittings 21 and 22to approximately level the main frame of the boat hoist assembly, andthen setscrews 25 and 26 are tightened to hold the assembly in thatposition, and with the lower ends of the tubular members 23 and 24extending down into the ground under supporting plates 27 and 28 whichfirmly rest on the latter.

The threaded rod 36 carrying supporting plate 39 is then adjusteddownward and anchored so that supporting plate 39 firmly rests on theground under same. Adjusting nuts 37 and 38 are then tightened to holdsupporting plate 39 in this position. The forward end of the boat hoistassembly has its supporting plates 29 and 30 also firmly resting on theground under same. With the assembly thus in place as shown in FIGURE 2,the front and rear supporting assemblies 58 and 40 are then lowered tothe dashed-line position shown. A boat 55 may then be moved onto thethus lowered front and rear supporting assemblies 58 and 40 and liftedby conventionally operating the winch 80 to pivotally move saidsupporting assemblies and raise the boat out of the water tentatively tothe position shown in FIGURE 2.

When it is time to use the boat again, it is only a matter of operatingthe winch 80 to lower said front and rear supporting assemblies 58 and40 together with the boat, and then leave said front and rear supportingassemblies lowered ready for use again when the boat is returned toelevating position over same. It is thus to be seen that a boat hoistassembly has been provided which is simple and positive in construction,and meets the objectives set forth. While directional terms such asupper, lower, et cetera, have been used in connection with thisinvention, it is to be understood that they have been solely used tofacilitate description of the invention in the position illustrated, andare not to be considered as a limitation of the invention.

Other modes of applying the principle of my invention may be employedinstead of those explained, change being made as regards the boat hoistapparatus herein disclosed, provided the means stated by any of thefollowing claims or the equivalent of such stated means be employed.

I therefore particularly point out and distinctly claim as my invention:

1. A boat hoist comprising a main frame having sides and front and rearends, a front supporting means having upper and lower ends, meanspivotally mounting the lower end of same on said front end of said mainframe, a rear supporting means having upper and lower ends, meanspivotally mounting the lower end of same on said rear end of said mainframe, means connecting said front and rear supporting means forsimultaneous movement of same, said front and rear supporting membershaving boat supporting means on the upper end of same remote from theirpivot mounting means, a connecting means, said connecting means beingsubstantially centered between said main frame side members, meansjoining said connecting means to said main frame at the front and rearportions of same, an operating link pivotally joined at one end to theupper end portion of said front supporting means, means slidably joiningthe other end of said operating link to said connecting means formovement in a direction lengthwise of same, said movement of the end ofsaid operating link along said connecting means toward said front end ofsaid frame pivotally moving said front and rear supporting means toelevate the boat supporting members mounted thereon, and means formoving the end of said operating link along said connecting means,wherein said means connecting said front and rear supporting means forsimultaneous movement of same is fixedly joined at one end to the upperend portion of said rear supporting means and at its front end to saidfront supporting means through said operating link at a point belowwhere the latter is pivotally connected to the upper end portion of saidfront supporting means and remote from the lower end of said operatinglink to facilitate operating movement of said lower end of the operatinglink on said connection means.

2. A boat hoist comprising a main frame having sides and front and rearends, a front supporting means having upper and lower ends, meanspivotally mounting the lower end of same on said front end of said mainframe, a rear supporting means having upper and lower ends, meanspivotally mounting the lower end of same on said rear end of said mainframe, means connecting said front and rear supporting means forsimultaneous movement of same, said front and rear supporting membershaving boat supporting means on the upper end of same remote from theirpivot mounting means, a connecting means, said connecting means beingsubstantially centered between said main frameside members, meansjoining said connecting means to said main frame at the front and rearportions of same, an operating link pivotally joined at one end to theupper end portion of said front supporting means, means slidably joiningthe other end of said operating link to said connecting means formovement in a direction lengthwise of same, said movement of the end ofsaid operating link along said connecting means toward said front end ofsaid frame pivotally moving said front and rear supporting means toelevate the boat supporting members mounted thereon, and means formoving the end of said operating link along said connecting means,wherein said connecting means, along which said operating link ismovable, has an adjustable supporting means substantially midlength ofsame.

3. A boat hoist comprising a main frame having sides and front and rearends, a front supporting means having upper and lower ends, meanspivotally mounting the lower end of same on said front end of said mainframe, a rear supporting means having upper and lower ends, meanspivotally mounting the lower end of same on said rear end of said mainframe, means connecting said front and rear supporting means forsimultaneous movement of same, said front and rear supporting membershaving boat supporting means on the upper end of same remote from theirpivot mounting means, a connecting means, said connecting means beingsubstantially centered between said main frame side members, meansjoining said connecting means to said main frame at the front and rearportions of same, an operating link pivotally joined at one end to theupper end portion of said front supporting means, means slidably joiningthe other end of said operating link to said connecting means formovement in a direction lengthwise of same, said movement of the end ofsaid operating link along said connecting means toward said front end ofsaid frame pivotally moving said front and rear supporting means toelevate the boat supporting members mounted thereon, and means formoving the end of said operating link along said connecting means,wherein said main frame has supporting means for same at each endthereof, and means at least at one end of said frame adjustably carryingand releasably anchoring said supporting means thereon for operativelypositioning and leveling said main frame, and wherein said connectingmeans, along which said operating link is movable, has an adjustablesupporting means substantially midlength of same.

4. A boat hoist comprising a main frame having sides and front and rearends, a front supporting means having upper and lower ends, meanspivotally mounting the lower end of same on said front end of said mainframe, a rear supporting means having upper and lower ends, meanspivotally mounting the lower end of same on said rear end of said mainframe, means connecting said front and rear supporting means forsimultaneous movement of same, boat supporting members mounted on saidfront and rear supporting members remote from said pivot mounting meansof same, a connecting means, said connecting means being substantiallycentered between said main frame side members, means joining saidconnecting means to said main frame at the front and rear portions ofsame, an operating link pivotally joined at one end to the upper endportion of said front supporting means, means slidably joining the otherend of said operating link to said connecting means for movement in adirection lengthwise of same, said movement of the end of said operatinglink along said connecting means toward said front end of said framepivotally moving said front and rear supporting means to elevate theboat supporting members mounted thereon, an upright member at one cornerof said main frame at the front end of same, means stabilizing saidupright member on said main frame, a winch mounted on said uprightmember at a point remote from said main frame, means connecting saidwinch to the lower end of said operating link for pulling same towardsaid front cross rail and elevating said front and rear supportingmeans, and means for operating said winch.

5. A boat hoist as set forth in claim 4, wherein said means connectingsaid inch to the lower end of said operating link is in the form of acable and pulley system, and said means for operating said winch is inthe form of a crank.

6. A boat hoist as set forth in claim 4, wherein said main frame hassupporting means for same at each end thereof, and means at least at oneend of said frame adjustably carrying and releasably anchoring saidsupporting means thereon for operatively positioning and leveling saidmain frame.

7. A boat hoist as set forth in claim 5, wherein said main frame hassupporting means for same at each end thereof, and means at least at oneend of said frame adjustably carrying and releasably anchoring saidsupporting means thereon for operatively positioning and leveling saidmain frame.

8. A boat hoist as set forth in claim 4, wherein said means connectingsaid front and rear supporting means for simultaneous movement of sameis fixedly joined at one end to the upper end portion of said rearsupporting means and at its front end to said front supporting meansthrough said operating link at a point below where the latter ispivotally connected to said front supporting means and remote from thelower end of said operating link to facilitate operating movement ofsaid lower end of the operating link on said connecting means.

9. A boat hoist as set forth in claim 4, wherein said connecting means,along which said operating link is movable, has an adjustable supportingmeans substantially midlength of same.

10. A boat hoist as set forth in claim 5, wherein said connecting means,along which said operating link is movable, has an adjustable supportingmeans substantially midlength of same.

11. A boat hoist comprising a main frame having sides and front and rearends, a front supporting means having upper and lower ends, meanspivotally mounting the lower end of same on said front end of said mainframe, a rear supporting means having upper and lower ends, meanspivotally monuting the lower end of same on said rear end of said mainframe, means connecting said front and rear supporting means forsimultaneous movement of same, boat supporting members pivotally mountedon said front and rear supporting members remote from said pivotmounting means of same, a connecting means, said connecting means beingsubstantially centered between said main frame side members, meansjoining said connecting means to said main frame at the front and rearportions of same, an operating link pivotally joined at one end to theupper end portion of said front supporting means, means slidably joiningthe other end of said operating link to said connecting means formovement in a direction lengthwise of same, said movement of the end ofsaid operating link along said connecting means toward said front end ofsaid frame pivotally moving said front and rear supporting means toelevate the boat supporting members mounted thereon, an upright memberat one corner of said main frame at the front end of same, brace meansconnecting said upright member to a bottom side rail and to the frontcross rail, a winch of conventional releasable latch type mounted onsaid upright member at a point remote from said main frame, said winchhaving a drum, a cable and pulley system connecting the drum of saidwinch to the lower end of said operating link for pulling the lattertoward said front cross rail when said cable is wound on the drum ofsaid winch, a crank for rotating the drum of said winch, said meansconnecting said front and rear supporting means for simultaneousmovement of same being fixedly joined at one end to the upper portion ofsaid rear supporting means and at its front end to said front supportingmeans through said operating link at a point below where the latter ispivotally connected to the upper end portion of said front supportingmeans and remote from the lower end of said operating link so as toapply a rearward pull on said operating link in opposition to the pullof said cable, and an adjustable supporting means for said connectingmeans located substantially midlength of the latter.

References Cited by the Examiner UNITED STATES PATENTS 1,976,978 10/34Allen. 2,963,176 12/60 Smith. 3,021,965 2/62 Harvey. 3,083,540 4/63Smith.

FOREIGN PATENTS 548,933 10/42 Great Britain.

GERALD M. FORLENZA, Primary Examiner.

MARVIN A. CHAMPION, Examiner.

1. A BOAT HOIST COMPRISING A MAIN FRAME HAVING SIDES AND FRONT AND REARENDS, A FRONT SUPPORTING MEANS HAVING UPPER AND LOWER ENDS, MEANSPIVOTALLY MOUNTING THE LOWER END OF SAME ON SAID FRONT END OF SAID MAINFRAME, A REAR SUPPORTING MEANS HAVING UPPER AND LOWER ENDS, MEANSPIVOTALLY MOUNTING THE LOWER END OF SAME ON SAID REAR END OF SAID MAINFRAME, MEANS CONNECTING SAID FRONT AND REAR SUPPORTING MEANS FORSIMULTANEOUS MOVEMENT OF SAME, SAID FRONT AND REAR SUPPORTING MEMBERSHAVING BOAT SUPPORTING MEANS ON THE UPPER END OF SAME REMOTE FROM THEIRPIVOT MOUNTING MEANS, A CONNECTING MEANS, SAID CONNECTING MEANS BEINGSUBSTANTIALLY CENTERED BETWEEN SAID MAIN FRAME SIDE MEMBERS, MEANSJOINING SAID CONNECTING MEANS TO SAID MAIN FRAME AT THE FRONT AND REARPORTIONS OF SAME, AN OPERATING LINK PIVOTALLY JOINED AT ONE END TO THEUPPER END PORTION OF SAID FRONT SUPPORTING MEANS, MEANS SLIDABLY JOININGTHE OTHER END OF SAID OPERATING LINK TO SAID CONNECTING MEANS FORMOVEMENT IN A DIRECTION LENGTHWISE OF SAME, SAID MOVEMENT OF THE END OFSAID OPERATING LINK ALONG SAID CONNECTING MEANS TOWARD SAID FRONT END OFSAID FRAME PIVOTALLY MOVING SAID FRONT AND REAR SUPPORTING MEANS TORELEVATE THE BOAT SUPPORTING MEMBERS MOUNTED THEREON, AND MEANS FORMOVING THE END OF SAID OPERATING LINK ALONG SAID CONNECTING MEANS,WHEREIN SAID MEANS CONNECTING SAID FRONT AND REAR SUPPORTING MEANS FORSIMULTANEOUS MOVEMENT OF SAME IS FIXEDLY JOINED AT ONE END TO THE UPPEREND PORTION OF SAID REAR SUPPOTING MEANS AND AT ITS FRONT END TO SAIDFRONT SUPPORTING MEANS THROUGH SAID OPERATING LINK AT A POINT BELOWWHERE THE LATTER IS PIVOTALLY CONNECTED TO THE UPPER END PORTION OF SAIDFRONT SUPPORTING MEANS AND REMOTE FROM THE LOWER END OF SAID OPERATINGLINK TO FACILIATE OPERATING MOVEMENT OF SAID LOWER END OF THE OPERATINGLINK ON SAID CONNECTION MEANS.